Procedure, Field Replacement, Level Cage Kit, Base Exit
Page
1
of
9
Document No
135266 Rev B
Copyright © Sea Tel, Inc 2011 - The information contained in this document is proprietary to Sea
Tel, Inc.. This document may not be reproduced or distributed in any form without prior written
consent of Sea Tel, Inc.
1.
Brief
Summary:
Troubleshooting
document
for
diagnosing
a
fault
with
and
replacing
the
level
cage
assembly.
2.
Checklist:
Verify
Remote
Tilt
Verify
Initialization
Verify
Sensor
Outputs
using
DacRemP
Azimuth
and
Relative
Targeting
Drift
and
Sensor
Monitoring
3.
Theory
of
Operation:
The
level
cage
contains
4
sensors.
These
are
a
fluid
filled
tilt
sensor
which
is
used
as
the
systems
horizon
reference
(level
position)
and
long
term
stabilization
reference,
and
3
solid
state
rate
sensors,
one
for
each
axis
which
acts
as
the
antennas
short
term
stabilization
reference.
A
faulty
sensor
inside
the
level
cage
will
cause
the
antenna
to
lose
stability
and
mispoint
from
the
satellite
under
dynamic
conditions
although
the
system
may
appear
to
be
operational
in
the
port
when
there
is
no
motion
to
counteract.
This
document
will
run
through
testing
the
sensors
inside
the
level
cage,
replacing
the
level
cage
assembly
and
calibrating
the
systems
remote
tilt
setting.
4.
Verify
Remote
Tilt:
If
the
pedestal
is
having
stability
problems
firstly
check
the
remote
tilt
setting
by
looking
at
the
level
bubble
on
top
of
the
level
cage
(note:
older
systems
didn’t
have
a
bubble
installed
on
top
of
the
level
cage).
If
the
bubble
isn’t
as
close
to
central
as
possible
the
remote
tilt
setting
isn’t
correctly
calibrated,
meaning
the
rate
sensors
won’t
be
correctly
aligned
with
their
axis.
This
will
cause
the
rate
sensors
to
output
incorrect
feedback
into
the
PCUs
control
loop,
potentially
causing
a
stabilization
issue.
Calibrate
the
remote
tilt
setting
as
per
the
instructions
at
the
end
of
this
document
and
continue
to
test
the
level
cage
using
the
follow
procedures.
5.
Verify
Initialization:
Power
cycle
the
pedestal
1.
Brakes
release
(if
applicable)
2.
Level
cage
drives
to
its
end
stop,
then
backs
off
exactly
45
degrees
3.
Elevation
axis
drives
to
45
degrees
based
on
the
level
cages
horizon
reference
4.
Cross
level
axis
drives
to
level
based
on
the
level
cages
horizon
reference
5.
Unlimited
azimuth
systems
drive
clockwise
until
the
home
flag
and
sensor
make
contact
6.
Limited
azimuth
systems
drive
clockwise
into
the
azimuth
end
stop,
then
back
off
to
630
degrees
of
relative
If
any
of
these
steps
fail,
or
the
ACU
reports
model
"xx03/xx04",
the
antennas
N0
parameter
needs
calibrating
and
verified
it
saves
correctly.
A
drive
issue
or
pedestal
error
requires
further
troubleshooting.
Summary of Contents for Base Exit
Page 1: ......
